Author: Robert Hyatt
Date: 08:37:56 09/08/00
Go up one level in this thread
On September 08, 2000 at 11:14:45, leonid wrote:
>Hi!
>
>Please solve two mate containing positions.
>
>First is almost from the book. Just changed it a little bit to make it search
>for mate three moves deeper.
>
> rnb3kr/pp3pp1/7p/3q3N/3pN3/Q7/PPP2KPP/R1B1R3 w
4-> 0.23 13.32 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Nf4+ Kf5 5. Nxd5 Be6
5 0.23 ++ 1. Nef6+!!
5 0.42 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
5-> 0.49 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
6 1.25 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
6-> 1.46 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
7 4.51 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
7-> 8.04 Mat07 1. Nef6+ gxf6 2. Re8+ Kh7 3. Rxh8+
Kg6 4. Rxh6+ Kf5 5. Rxf6+ Ke4 6. Qf3+
Ke5 7. Bf4#
>
>I don't know how much this position could take if solved by brute force. When I
>found that 6 moves took already on my program 2 min 15 sec., looked for mate in
>7 only by selective search.
>
> 2rkr3/n1ppp1n1/2q1q3/NN1N1NN1/2NRN3/8/2R1R3/3K4 w
6 3.28 25.87 1. Nxa7 Rh8 2. N5xc6+ Ke8 3. Nxg7+
Kf8 4. N7xe6+ dxe6 5. Nxe6+ Kf7 6.
N4g5+ Kg6 7. Nxc8 Rxc8
6-> 7.02 25.87 1. Nxa7 Rh8 2. N5xc6+ Ke8 3. Nxg7+
Kf8 4. N7xe6+ dxe6 5. Nxe6+ Kf7 6.
N4g5+ Kg6 7. Nxc8 Rxc8
7 7.10 ++ 1. Nxa7!!
7 11.11 28.88 1. Nxa7 Rh8 2. N5xc6+ Ke8 3. Nxg7+
Kf8 4. N7xe6+ dxe6 5. Nxe6+ Ke8 6.
Nxc8 Kf7
7-> 31.81 28.88 1. Nxa7 Rh8 2. N5xc6+ Ke8 3. Nxg7+
Kf8 4. N7xe6+ dxe6 5. Nxe6+ Ke8 6.
Nxc8 Kf7
8 32.20 ++ 1. Nxa7!!
8 54.22 Mat08 1. Nxa7 Rh8 2. N7xc6+ Ke8 3. Nxg7+
Kf8 4. N7xe6+ dxe6 5. Rf2+ Kg7 6. Rf7+
Kg6 7. N4e5+ Kh5 8. Rh2#
>
>This fantasy position I tried to do as accessible for every program as possible.
>Looked for number of nodes in the ply to be never more that 100.
>
>In this position (also created today) I don't know exact number of minimum moves
>that could lead to the mate. I know only that it is between 7 and 8. Was too
>long for me to see this by brute force. 6 moves revision took already 48 min
>(AMD 400Mhz). Mate is solved only by selective search 8 moves deep in 0.1 sec.
>
>Please, indicate as much about all your main parameters as you can. Try not
>forget your program name, hash size, selective or brute force search, speed of
>your computer and so like.
>
>Will be especially interested to know what impact on your search make your hash
>table. I don't have hash in my program to try. When I solved one position
>recently on Rebel 10, difference was spectacular. For 6 moves search, almost 6
>fold. Rebel's hash was 28 M. With other comercial programs I can't see this that
>clearly. They almost never permit to put hash size to zero.
>
>Thanks,
>Leonid.
Done by crafty, hash=48M, machine=PII/400 notebook (Sony).
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